142 _ 
regarded as equivalent to the body dyed red in the example 
in fig. 7, that is, presumably homologous with the vesicula 
intima (‘‘ Binnenblase,” Haeckel). If, indeed, this be really 
so, then it may be asked where is the structure surrounding it 
or the “central capsule”’ itself ? Perhaps, then, the answer to 
this query may be that the latter is not yet formed, and that 
the “‘vesicula intima” is the first produced. On this point I 
may call to mind that Haeckel himself informs us that there is 
a time in the young condition of a veritable and altogether 
typical marine Radiolarian, in which no “ central capsule” 
exists.! 
Having thus, in the case of A. spinifera, been able to 
demonstrate, at least in undoubted typical examples, two 
differentiated structures, one within the other, which may 
seemingly as yet legitimately be interpreted as “ central 
capsule” and “ inner vesicle” (“‘ Central-kapsel” and ‘‘ Binnen- 
blase”), I was naturally desirous to experiment upon the 
form described by myself in my preceding fasciculus, dcan- 
thocystis Pertyana, and, fortunately, some specimens lately 
turned up, though I regret I have been unable to prepare a 
figure in time for insertion in the present plate. In my 
previous description of 4. Pertyana! stated that no “central 
capsule” nor * nucleus” could be made out, nor, indeed, can 
such be perceived by mere examination of an ordinary living 
example; it is to be regretted that I had not at command at 
that time Beale’s useful carmine fluid, for its application has 
disclosed at least an equivalent structure to that in A. spini- 
fera. In A. Pertyana, however, the result of the application of 
this reagent was not quite the same as in the case of A. spini- 
era; for though a smaller round central body took quite as 
high a colour as that in that species, yet, unlike it, the 
presumable ‘central capsule” likewise became comparatively 
highly coloured, but by no means so intensely as the more 
minute inner body, both one and the other becoming in- 
dividually very clearly marked off, each with a sharp outline. 
Of course the appearances presented in even both forms, 
resulting from the experiment described, might be capable of 
a different interpretation—that is, that these structures, in . 
place of “central capsule” and “inner vesicle,” may re- 
present rather “nucleus” and “nucleolus;” but I should 
myself as yet be more disposed to accept the former view, 
supported as it is by the analogy of the structure of the 
marine forms—a view in which I imagine most other ob- 
servers will rather be inclined to acquiesce. Bearing on this 
1 Loe. cit., p. 530. 
